Questions about STM32 adc driver layout.

[Sandvoxel]

Hello Embassy Team,

I have a question regarding the structure of the STM32 ADC driver. I understand that the design must accommodate specifying the pin for measurement, but I have noticed some inconsistencies compared to other drivers.

Currently, there is a trait for a single channel, AdcChannel, and an abstraction, AnyAdcChannel. It appears that AnyAdcChannel has not been updated with the new PeripheralType trait, which prevents its use in contexts such as:

voltage_sense: Peri<'a, impl AdcChannel<T>>,

This oversight limits the ability to store ADC channels in structs. While I understand that the degrade_adc function allows conversion between types, I believe it should be possible to directly use voltage_sense.into(), similar to how other peripherals operate.

Thank you for your time and assistance.

I am currently working with the relatively new adc driver for the stm32u5.

[Sandvoxel]

For some more context I'm trying to make a general purpose struct for handling power buses. I'm also willing to concede that I may just be going out this the wrong way. It just feels so wrong making it store the specific peripheral instead of the generalized definition.

[i509VCB]

Looking at the docs, it appears that AnyAdcChannel implements PeripheralType: https://docs.embassy.dev/embassy-stm32/git/stm32u595ri/adc/struct.AnyAdcChannel.html#impl-PeripheralType-for-AnyAdcChannel%3CT%3E

You might need an into() to go from the concrete adc channel type to a Peri<'a, AnyAdcChannel>

[Sandvoxel]

Doing this as sugested leads to a different Error as Peri Expects a trait.

impl<'a, T: Instance> VoltageMonitor<'a, T> {
    pub fn new(
        enable: Output<'a>,
        reset: Output<'a>,
        voltage_sense: Peri<'a, impl AnyAdcChannel>,
        current_sense: Peri<'a, impl AnyAdcChannel>,
    ) -> Self {

        Self {
            enable,
            reset,
            voltage_sense: voltage_sense.into(),
            current_sense: current_sense.into(),
        }
    }
}

error[E0404]: expected trait, found struct `AnyAdcChannel`
   --> src/voltage_monitor/mod.rs:20:38
    |
20  |         voltage_sense: Peri<'a, impl AnyAdcChannel>,
    |                                      ^^^^^^^^^^^^^ help: a trait with a similar name exists: `AdcChannel`
    |
   ::: /Users/kylekovalchick/Documents/projects/embassy/embassy-stm32/src/adc/mod.rs:142:1
    |
142 | pub trait AdcChannel<T>: SealedAdcChannel<T> + Sized  {
    | ---------------------------------------------------- similarly named trait `AdcChannel` defined here